Since the 1950s, Americans have been told saturated fats and cholesterol in our diets was killing us by significantly increasing our risks of heart disease and stroke.

Since the 1950s, Americans have been told saturated fats and cholesterol in our diets was killing us by significantly increasing our risks of heart disease and stroke. This assumption is based on a study by University of Minnesota researcher Ancel Keys. In his Seven Countries Study, he compared the diet of Americans with the diet of people in six other countries and determined that Americans ate the most fat and had the most deaths related to heart disease and stroke.

Based on this correlation, the American Heart Association first began to advise us to limit our animal fat (saturated fat and cholesterol) intake in 1956. In 1977, Congress put in place the first government policy recommending a low-fat diet. In response, manufacturers began producing reduced-fat processed foods, and margarine was the recommended fat of choice.

Fats in our diet were reduced, and we replaced those calories with sugars and carbohydrates. Manufacturers encouraged this by flooding the market with re-engineered products that were low in fat, but loaded with sugar, refined carbohydrates and calories. And because we now lacked the fats in our diet that helped make us feel full, we ate double or triple the portions. Guess what happened … we became fatter, and the incidence of heart disease continued to rise.

In 1960, 45 percent of our diet consisted of fats or oils. Thirteen percent of the population was obese, and just 1 percent had diabetes. Today, the average diet consists of 33 percent fat, our obesity rate is 34 percent and climbing, and 11 percent of the population now has diabetes.

How did our efforts to decrease fat, especially animal fat, in our diet fail? Let’s start with some criticism of the Keys study. It seems he actually collected data from 22 countries but only used the seven that would prove his hypothesis. He did not take into account any other diet habits, smoking or activity levels. Additional early studies were based on animal studies and short-term trials that measured cholesterol levels but not whether the participants actually had heart attacks.

Since this study, there have been many that have failed to prove the link between saturated fat and heart disease. The Women’s Health Study Initiative in 2004 studied the diets of 20,000 women during an eight-year period. It determined that a low-saturated-fat diet did not decrease the risk of heart disease or stroke. Another study in 2010, published in the American Journal of Clinical Nutrition, summed up the results of 21 studies involving 350,000 people. It concluded there is no proof of a link between saturated fat in the diet and heart disease.

Many experts believe the increased sugars and refined grains in our diet are harming us more than dietary fats. When carbohydrates enter the bloodstream, they convert to sugar; this prompts insulin to be released. If we do not need the calories for energy, insulin prompts this sugar to be stored as fat and triglycerides. Unfortunately, we often cannot use as many calories as we eat, so we gain weight. Obesity is a known risk factor for heart disease. Studies have also shown that a high-carbohydrate, low-fat diet increases the density of LDL particles. Small/dense LDL particles pose 4 times the risk of clogged arteries, compared to the larger, “fluffier” LDL particles.

We now know that saturated fat isn’t just a single fat, but rather there are more than two dozen types of saturated fat. The top four are as follows.

Pamitic and Myristic acids (found in palm oil, butter, eggs, cheese, milk, butter) appear to raise LDL cholesterol but they also increase particle size, making the LDL less dangerous. They also raise HDL cholesterol proportionately. This type of saturated fat is considered to have a neutral effect on our health.

Stearic Acid (found in chocolate and beef) does not raise LDL cholesterol levels and has no negative effect on our health.

Lauric Acid (found in coconut oil) doesn’t appear to be harmful, but these fats do not have an edge over other oils, like olive oil, whose positive benefits have been well studied and proven.

Although saturated fat itself may not be contributing to heart disease, the foods we eat probably are. The top three sources for saturated fat in the American diet are cheese, pizza and grain-based desserts. These are foods that are also high calorie, have high levels of sodium, added sugars and trans fats.

When five dietary patterns, including a high-trans-fat diet, a high-saturated-fat diet, a high-sodium diet, a diet low in fruits and vegetables, and a diet low in omega 3 fatty acids (which pretty much describes the typical American diet) are compared to the deaths associated with each, the high saturated fat diet comes in last.

Bottom line:

Pay attention to the whole food you are eating, rather than select components like saturated fat or cholesterol.

Replace saturated fats with the healthiest fats — like olive oil, canola oil, avocados, nuts and fish — not carbohydrates.

Avoid trans fats, or partially hydrogenated fats. We are certain these fats are the worst.

Get your carbs from fruits, vegetables and whole grains, not from sugary or refined starches.

Eat real food, but not too much of anything.

Anita Marlay, R.D., L.D., is a dietitian in the cardiac rehab department at Lake Regional Health System in Osage Beach, Mo.